Recent important trends in electronic industries are increase of wireless and mobile devices and conversion from analog to digital. Rapid popularization of wireless telephone (mobile phones) and laptop computers and conversion from analog cameras to digital cameras are representative examples of the trends.
In company with the above-mentioned trends, much research and development on secondary batteries as a power source for the devices has been carried out. One of the secondary batteries is a lithium secondary battery, which uses lithium transition metal oxide or lithium composite oxide as cathode active material, and has a high output and capacity to weight ratio, whereby the lithium secondary battery is in the spotlight. The lithium secondary battery is constructed in a structure in which an electrode assembly, which is constructed in a cathode/a separator/an anode structure, is mounted in a sealed case together with an electrolyte. However, the lithium secondary battery has problems in that the lithium secondary battery may catch fire or explode due to overcharge, overdischarge, overcurrent, or external impacts, i.e., the lithium secondary battery has low safety.
In order to solve the problems, the secondary battery is provided with various safety elements. For example, a protection circuit module (PCM), which interrupts supply of electric current at the time of overcharge, overdischarge, or overcurrent so as to secure the safety of the battery, is connected between a battery cell and external input and output terminals. The use of such safety elements is one of major factors increasing the manufacturing costs of the battery.
As a result, non-genuine product batteries have been increasingly used. In the case of batteries having no safety elements, however, there is a high possibility of danger in that the batteries can catch fire or explode due to the abnormal operation of the batteries. It has been occasionally reported that non-genuine product batteries have exploded during the use of devices while the non-genuine product batteries were mounted in the devices. Consequently, a method or system for identifying genuine product batteries, i.e., batteries having all elements necessary to secure the operation and the safety of the batteries, is required. However, it becomes more difficult to distinguish appearance between genuine product batteries and non-genuine product batteries due to development of an imitation technology.
Meanwhile, in connection with the product identification, there has been widely used in recent years a technology of identifying data stored in a tag having a microchip mounted therein using radio frequency in a non-contact fashion, which is a kind of automatic identification and data capture (AIDC) technology, in distribution and logistics applications. Radio frequency identification (RFID) is a kind of AIDC technology, which reads data from a tag, a card, or a label having a microchip mounted therein using radio frequency in a non-contact fashion. The RFID system is a radio frequency system comprising a tag semiconductor chip, an antenna, and a reader (an identifier).
Product information of a product, to which the tag is attached, is stored in the semiconductor chip. The antenna transmits the information by a distance of a few meters to dozens of meters in the form of radio frequency. The reader receives the signal to decode the product information and transmits the decoded product information to a predetermined system, such as a computer. Consequently, all products having a tag attached thereto can be automatically identified or tracked anywhere at any time.
The RFID can be accurately classified based on classification criteria, such as whether power is supplied or not, frequency band, and communication connection. Depending upon whether power is supplied or not, the tag may be classified as an active tag or a passive tag. The active tag has advantages in that the active tag uses a built-in battery, has readable/writable memories of various sizes, and has a long-distance (30 to 100 m) data exchange range. On the other hand, the passive tag has advantages in that, the passive does not require supply of external power, whereby the structure of the passive tag is relatively simple, the manufacturing costs of the passive tag is low, and the passive tag has a semi-permanent service life. However, the memory of the passive tag is a read only memory, and the passive tag requires a high-output reader. Consequently, the passive tag is used in small-unit applications.
Depending upon the frequency band, the tag may be classified as a high frequency tag or a low frequency tag. The low frequency tag uses a frequency of 30 to 500 KHz with the result that the readable distance of the low frequency tag is short. Consequently, the low frequency tag is usually utilized in security, proper management, and genuine product identification applications. On the other hand, the high frequency tag uses a frequency of 860 to 960 MHz or 2.45 GHz with the result that the readable distance of the low frequency tag is long, for example, 30 m or more. Consequently, the low frequency tag is usually utilized in railroad, logistics, and distribution applications.